The present invention pertains generally to filters. More particularly, the present invention pertains to filters for carpet cleaning devices. The present invention is particularly, but not exclusively, useful as a filter which continually removes synthetic fibers and other insoluble debris from a wastewater stream which is generated by operation of the carpet cleaning device.
Carpet cleaning devices are known in the prior art. Certain types of these devices use water as the primary agent for cleaning a carpet. For water-based devices, the carpet cleaning process generates a wastewater stream which must be properly disposed of once the process is completed.
Various local, state and federal agencies, as well as industry organizations, have developed guidelines for proper on-site disposal of wastewater from a carpet cleaning process. For example, disposal of wastewater within a sanitary sewer system at the site is allowed under certain conditions. Alternatively, on-site land wastewater disposal is allowed under certain conditions if permission is obtained from the property owner. But no matter which manner of on-site disposal is required, an initial pre-filtering step is almost always required to remove synthetic carpet fibers and other insoluble debris from the wastewater stream.
Carpet cleaning devices are typically mounted in mobile units, such as trucks or vans. For these mobile units, space is a consideration, and the devices should be small and take up as little space as possible. Thus, many of these devices do not include the additional equipment for continuously removing the synthetic fibers and debris during operation, which would allow for on-site disposal of the wastewater. Instead, in order to comply with federal/state/industry guidelines, most vehicles have a large holding tank for holding the wastewater stream for further transportation back to their place of business. Unfortunately, such a configuration is unwieldy and inefficient. Time and money is lost because the mobile unit must return to the business location in order to dispose of the wastewater in the holding tank before moving on to the next cleaning job, unless the mobile unit illegally dumps the wastewater into a nearby storm drain to save time. Further, the holding tank takes up valuable cargo space in the mobile unit.
U.S. Pat. No. 5,430,910, which issued to Wiley for an invention entitled xe2x80x9cCarpet Cleaning Apparatusxe2x80x9d, discloses a separation vessel with a first and second annular space for removing air from a wastewater stream. Wiley discloses a sealed outer shell, an air tube coaxially installed in the shell, and a liquid tube installed around the air tube in a spaced apart relationship. This forms a first and second annular space within the shell.
In Wiley, however, the lower portions of the respective first and second annular spaces are in fluid communication with each other. This is not an effective arrangement for allowing insoluble debris to settle at the bottom of the tank. Additionally, Wiley""s shell i is sealed and does not provide for access. This is because Wiley does not remove debris from the wastewater. His device is merely designed for removing air from the wastewater stream.
U.S. Pat. No. 5,430,910, which issued to Sprinkle for an invention entitled xe2x80x9cSelf-Contained, Closed-Loop, Hard Surface and Carpet Cleaning Apparatusxe2x80x9d, discloses a gravity separation unit with a housing having an interior wall that establishes two separate chambers within the housing. Sprinkle, however, does not disclose a U-shaped siphon which establishes fluid communication between the two chambers, nor does Sprinkle disclose an angled connection for taking a secondary suction from one of the chambers.
In view of the above, it is an object of the present invention to provide a filter for a carpet cleaning device which is portable and which can be mounted in a mobile unit. It is another object of the present invention to provide a filter for a carpet cleaning device which continually removes synthetic fibers and non-biodegradable debris from a generated wastewater stream of a carpet cleaning device, while the device is in operation. Another object of the present invention is to provide a filter for a carpet cleaning device which obviates the need for a holding tank for holding wastewater which includes fibers and insoluble debris. It is another object of the present invention to provide a filter for a carpet cleaning device which is relatively simple to use, is relatively easy to manufacture and is comparatively cost effective.
A filter for a carpet cleaning device in accordance with the present invention includes a casing and a partition which extends upwardly from the casing floor to define a primary chamber and a secondary chamber in the casing. As a wastewater/debris stream is transported into the filter, the stream is initially contained in the primary chamber. As the stream collects in the primary chamber, the debris settles at the bottom of the primary chamber and a primary fluid level of wastewater is further established therein.
A main siphon having an inverted U-shape is mounted in the partition to establish a path of fluid communication between the primary chamber and the secondary chamber. The main siphon has a horizontal section which merges into two opposing vertical portions that extend downwardly from the horizontal section into a respective primary chamber and secondary chamber.
The secondary chamber further includes an auxiliary siphon which is located in the secondary chamber. The auxiliary siphon comprises an auxiliary horizontal portion that is attached to the casing and a downturned auxiliary vertical portion which projects from the auxiliary horizontal portion in an angled configuration. The auxiliary horizontal portion is further connected to a pump.
The filter of the present invention also includes a filter basket which is removably placed within the filter and which rests on the partition edge when placed therein. The filter basket is manufactured with a primary compartment and a secondary compartment. When in place, the primary compartment of the basket is sized to correspond with the primary chamber, and the secondary compartment is sized to correspond with the secondary chamber when the basket is placed in the filter. The filter basket is located within the filter so that any wastewater/debris stream that is transported into the filter passes through the basket before entering the primary chamber. Thus, the filter basket functions to eliminate any larger chunks of debris from the wastewater stream before the stream enters the primary chamber. Once full, the filter basket is removed, and the debris is disposed of.
For the method of the present invention, a wastewater/debris stream from a carpet cleaning device is transported into a filter having the above-summarized structure. After larger pieces of debris are removed by the basket filter, the wastewater/debris stream enters the primary chamber, where it collect to establish a primary fluid level. As the primary fluid level rises, most of the debris settles at the bottom of the primary chamber.
When the above-mentioned primary fluid level becomes about even with the horizontal portion, a Venturi effect is created in the siphon (in accordance with known scientific principles) which causes wastewater to be transported through the main siphon from the primary chamber to the secondary chamber. As the wastewater enters the secondary chamber, it collects to establish a secondary fluid level therein. As the secondary fluid level rises, any remaining debris settles at the bottom of the secondary chamber. When the secondary fluid level reaches a predetermined level, the pump is selectively activated to remove wastewater (without debris) from the filter for further disposal.
With the filter and method of the present invention, xe2x80x9cprocessedxe2x80x9d wastewater (wastewater without debris) can be continually removed from the filter while simultaneously introducing a wastewater/debris stream into the filter. Stated differently, the filter and method of the present invention allow for sufficient processing of the wastewater so that the wastewater can be disposed of on-site, while the carpet cleaning device (which generates the wastewater/debris stream) is operating. This allows for increased efficiency and flexibility in the operation of mobile-mounted carpet cleaning devices in remote locations.